In recent years, demand for a rear projector is becoming increasingly strong as a suitable display for a monitor for a home theater, a large screen television, or the like.
In a transmission screen used for the rear projector, a lenticular lens is in general use. However, this type of screen has a problem that the vertical view angle thereof is small although the lateral view angle thereof is large (namely, there is a bias in the view angle).
As a solution to such a problem, there has been proposed a transmission screen which uses a microlens array (microlens substrate) in place of the lenticular lens. (see, for example, Japanese Laid-Open Patent Application No. 2000-131506). The transmission screen has an advantage that the view angle can be increased both in lateral and vertical directions.
Such a microlens array (microlens substrate) is normally manufactured by employing photolithography technology (see, for example, Japanese Laid-Open Patent Application No. 2001-341210). However, it is extremely difficult to manufacture a microlens array with a relatively large screen area such as those used for the rear projector by the conventional photolithography technology. For this reason, the rear projector is sometimes manufactured by combining a plurality of microlens arrays each having a relatively small screen area. However, in such a case, there is a problem that the joining lines of the microlens arrays show up in the projected image.